Patent Literature 1 below discloses this type of technique. In the technique disclosed in Patent Literature 1, a passage having a throttle hole which connects a high pressure chamber of a variable displacement vane pump with a power steering system is provided parallel to another passage having a load sensitive valve provided therein. The load sensitive valve opens when a steering wheel is turned to thereby supply a total of a flow rate of hydraulic fluid which passes through the throttle hole and a flow rate of hydraulic fluid which passes through the load sensitive valve to the power steering system.